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<title>Chapter 5: Program Loading and Dynamic Linking</title><p>
<h1>Introduction</h1><p>
This section describes the object file
information and system actions that create running programs.
Some information here applies to all systems;
information specific to one processor resides in
sections marked accordingly.
<p>
Executable and shared object files statically represent programs.
To execute such programs, the system uses the files to create
dynamic program representations, or process images.
As section ''Virtual Address Space'' in Chapter 3 of the 
processor supplement describes, a process image has segments that
hold its text, data, stack, and so on.  This chapter's major sections
discuss the following:
<ul>
<li>
<a href=ch5.pheader.html>Program Header.</a>
This section complements Chapter 4, describing
object file structures that relate directly to program execution.
The primary data structure, a program header table, locates
segment images within the file and contains other information
necessary to create the memory image for the program.
<li>
<a href=ch5.prog_loading.html>Program Loading.</a>
Given an object file, the system must load
it into memory for the program to run.
<li>
<a href=ch5.dynamic.html>Dynamic linking.</a> 
After the system loads the program it must complete
the process image by resolving symbolic references among the object
files that compose the process.
</ul>
<hr>
<img src=warning.gif alt="NOTE:">
The processor supplement defines a naming convention for ELF constants
that have processor ranges specified.  Names such as <code>DT_</code>,
<code>PT_</code>,
for processor specific extensions, incorporate the name of the
processor: <code>DT_M32_SPECIAL</code>, for example.
Pre-existing processor
extensions not using this convention will be supported.
<table>
<th>Pre-Existing Extensions</th>
<tr>
<td><code>DT_JUMP_REL</code></td>
</tr>
</table>
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